Abstract: Since ancient times travelers and tourists try to leave their marks in places they visit. However, carving or writing on historic landmarks can cause irreversible damage on such sites. One possible solution are digital graffiti. These can for example be created through projection mapping where beams of light wrap the object with the digital graffiti created by users so everyone at the site can see them. However this may disturb other visitors being there at the same time. In this paper we explore an alternative solution for creating digital graffiti by utilizing Mobile Augmented Reality (MAR) technology. We developed a mobile application which allows users to: (i) select an object or a building, (ii) map a 3D mesh onto it in order to prepare its 2D plane , and (iii) draw a graffiti on this plane. After completing the drawing the application wraps the object or the building with a modified 2D texture creating an illusion of digital graffiti. In order to (i) evaluate the social acceptance of placing digital graffiti onto historic landmarks and to (ii) evaluate if the use of our prototype is socially acceptable in public spaces, we carried out a small reflective user study. We created a couple of simple graffiti on different historic buildings and posted them on social networking site Facebook. Despite amateur appearance, posted photos received attention and generated some positive responses and questions.

Abstract: In this paper, we describe first prototype of mobile crowd sensing device. The device serves as a source for signals in the potential crowd sensing studies. Presented device has no intention to compete with the existing mobile devices, such as mobile phones, but to complement them where they lack of the features like affordability, simple use and new opportunities in different segments of our lives. Our main goal was to develop a device, which can cover all aspects of mobile crowd sensing and at the same time to keep the device cost at very affordable level. The described device is capable of integration into most widely available sunglasses. The complete device consisting of two separate “lenses” forms distributed ecosystem serving as source for sound, light, acceleration and temperature signals while at the same time providing actuator function with integrated LED matrix display.